Long-term results of visually guided left ventricular reconstruction as single therapy to treat ventricular tachycardia associated with postinfarction anteroseptal aneurysm

Procedural Adaptations to Avoid Haemodynamic Instability During Catheter Ablation of Scar-related Ventricular Tachycardia

Classically, catheter ablation for scar-related ventricular tachycardia (VT) relied upon activation and entrainment mapping of induced VT. Advances in post-MI therapies have led to VTs that are faster and haemodynamically less stable, because of more heterogeneous myocardial fibrosis patterns. The PAINESD score is one means of identifying patients at highest risk for haemodynamic decompensation during attempted VT induction, who may, therefore, benefit from alternative ablation strategies. One strategy is to use temporary mechanical circulatory support, although this warrants formal assessment of cost-effectiveness. A second strategy is to minimise or avoid VT induction altogether by employing a family of 'substrate'-based approaches aimed at identifying VT isthmuses during sinus or paced rhythm. Substrate mapping techniques are diverse, and focus on the timing, morphology and amplitude of local ventricular electrograms - sometimes aided by advanced non-invasive cardiac imaging modalities. In this review, the evolution of VT ablation over time is discussed, with an emphasis on procedural adaptations to the challenge of haemodynamic instability.

The severity of ventricular arrhythmia correlates with the extent of myocardial sympathetic denervation, but not with myocardial fibrosis extent in chronic Chagas cardiomyopathy : Chagas disease, denervation and arrhythmia

BACKGROUND

To investigate the correlation between the extent of myocardial sympathetic denervation and fibrosis and the presence of degrees of severity of ventricular arrhythmias in chronic Chagas cardiomyopathy (CCC).

METHODS

Forty-three CCC patients with left ventricular ejection fraction (LVEF) ≥ 35% were divided into three groups: SVT group-presenting Sustained Ventricular Tachycardia (SVT) (n = 15), NSVT group-exhibiting episodes of non-SVT (NSVT) on 24-h Holter monitoring (n = 11), and Control group-exhibiting neither SVT nor episodes of NSVT (n = 17). The patients underwent SPECT imaging for myocardial sympathetic innervation with 123Iodine-MIBG (MIBG) and myocardial perfusion with 99mTc-Sestamibi (MIBI) for the evaluation of regional myocardial fibrosis.

RESULTS

The summed rest perfusion scores were similar in the three groups. The summed difference score between MIBG and MPI images, which evaluated the extent of denervated but viable myocardium, was significantly higher in SVT group (20.0 ± 8.0) as compared with the control group (2.0 ± 5.0, P < .0001) and with the NSVT group (11.0 ± 8.0, P < .05).

CONCLUSIONS

The occurrence of ventricular arrhythmias of different degrees of severity correlates quantitatively with the extent of cardiac sympathetic denervation, but not with the extent of fibrosis, suggesting that myocardial sympathetic denervation plays a major role in triggering ventricular arrhythmia in CCC.

Left ventricular restoration: how important is the surgical treatment of ischemic heart failure trial?

If the Surgical Treatment of Ischemic Heart Failure (STICH) trial demonstrates that surgical therapy is superior to medical therapy, early aggressive evaluation of coronary artery disease as a potentially correctable cause of new-onset heart failure would be the preferred strategy. This strategy could tremendously change the treatment of ischemic heart disease. Confirming the STICH revascularization hypothesis will dramatically increase the use of coronary artery bypass grafting among the millions of patients now being medically treated without evaluation for an ischemic cause.

[The current evidence of S-1 and irinotecan hydrochloride combination chemotherapy with tri-weekly schedule]

A combination therapy of irinotecan hydrochloride (CPT-11) with continuous intravenous infusions of (infusional) 5-fluorouracil (5-FU) and Leucovorin (LV) is often used to treat advanced colorectal cancer. However, recent concerns on safety and convenience have prompted the development of new oral fluoropyrimidine derivatives which improved regimens. Yamada et al conducted a phase I study to assess the maximum tolerated dose and recommended dose of S-1 combined with CPT-11. The study recommended that 150 mg/m2 of CPT-11 be given on day 1 and 80 mg/m2 of S-1 daily on days 1 to 14 every 3 weeks. Recently, several phase I/II studies assessed the efficacy and safety of the combined therapy with S-1 and CPT-11 in patients with advanced colorectal cancer. Some of the studies which were ongoing assessed a tri-weekly schedule regimen. Our results showed that S-1 plus CPT-11 was very effective, with a response rate of 63% and PFS of 8 months. Toxicity was generally mild and manageable on an outpatient basis. The current evidence showed that a combination of S-1 and CPT-11 was more convenient and easier to administer than a combination of CPT-11 plus infusional 5-FU and LV. It will be essential to prove that the combination of S-1 plus CPT-11 can replace the combination of infusional 5-FU and LV plus CPT-11 without negatively affecting efficacy and toxicity.

Ventricular arrhythmias after LV remodelling: surgical ventricular restoration or ICD?

Ventricular arrhythmias cause ~50% of deaths in remodeled ventricles after myocardial infarction, and the Multicenter Automatic Defibrillator Implantation Trial (MADIT II) showed that the Implantable Cardioverter Defibrillator (ICD) saved lives in high risk coronary patients with advanced left ventricular dysfunction. We studied 382 patients with remodeled hearts by preoperative Ventricular stimulation (PVS) to evaluate surgical ventricular restoration (SVR) that excludes scar and lower ventricular volume alters the early and late arrhythmia process without ICD utilization.

METHODS

Clinical and hemodynamic results before and after SVR in post-infarction patients, are compared to contrast spontaneous and/or inducible ventricular tachycardia to patients without arrhythmias. Study arrhythmia groups included: Spontaneous in 87 patients with clinical documented ventricular arrhythmias and inducible or not inducible ventricular tachycardia: Inducible in 105 patients without clinical ventricular arrhythmias but PVS inducible ventricular tachycardia; and No arrhythmias in 190 patients without spontaneous or PVS inducible ventricular tachycardia.

RESULTS

Preoperative LV end systolic volume index helped define preoperative arrythmia potential: Spontaneous > 120/m(2), inducible > 100 ml/m(2), and none < 100ml/m(2). Overall operative mortality rate was 7.6% (29/382). Sudden cardiac death rate was 2.5% causing 18.7% of all deaths. Surgical management reduced inducible ventricular tachycardia, from 41% preoperatively (144/352) to 8% (26/307) at early study, and 8% (14/177) one year later. Cardiac mortality was low at 5-years and not different between groups, despite use of only one late ICD device.

CONCLUSIONS

Favorable electrical success rate and low mortality always included volume reduction to interrupt functional re-entry circuits, but also added endocardiectomy, cryoablation, CABG and mitral repair when needed. Overall SVR findings show volume and shape alteration limits ventricular arrhythmias that impair prognosis, and suggests ICD devices are not needed.

Surgical ventricular restoration in patients with postinfarction coronary artery disease: effectiveness on spontaneous and inducible ventricular tachycardia

Surgical ventricular reconstruction (SVR) involves resection of scar, septal exclusion, cavity reduction by endoventricular patch, and complete coronary grafting. At the Cardiothoracic Centre of Monaco, ventricular stimulation (PVS) is performed before SVR, unless contraindicated. In patients with spontaneous and/or inducible ventricular arrhythmias, nonguided endocardiectomy and cryosurgery are added. We report clinical and hemodynamic results after SVR in postinfarction patients, to compare management of patients with spontaneous and/or inducible ventricular tachycardia, with those without arrhythmias. The 3 subsets were: Group A, 87 patients with clinical documented ventricular arrhythmias and inducible or not inducible ventricular tachycardia (Spontaneous); Group B, 105 patients without clinical ventricular arrhythmias but with inducible ventricular tachycardia at PVS (Inducible); and Group C, 190 patients without spontaneous arrhythmias and not inducible ventricular tachycardia at PVS (No arrhythmias). Overall surgical mortality rate was 7.6% (29 of 382). Sudden death mortality was only 18.7% of all deaths. Surgical management caused marked reduction of inducible ventricular tachycardia, from 144 of 352 inducible ventricular tachycardia before surgery (41%), to 26 of 307 (8%) at early study, and 14 of 177 (8%) one year later. Cardiac mortality was low at 5 years, and not different among groups; this indicates that the surgical procedure limits the ventricular arrhythmias that normally impair prognosis in postinfarction dilated cardiomyopathy. We believe the favorable electrical success rate and low mortality are not linked to one aspect of the surgical procedure, but to an integrated approach that relieves ischemia (coronary bypass graft), and reduces left ventricular volumes (SVR) to improve pump function, and nonguided endocardiectomy plus cryoablation, to interrupt functional reentry circuits.

Nonsurgical transthoracic epicardial catheter ablation to treat recurrent ventricular tachycardia occurring late after myocardial infarction

OBJECTIVES

We sought to evaluate feasibility, safety and results of transthoracic epicardial catheter ablation in patients with ventricular tachycardia occurring late after an inferior wall myocardial infarction.

BACKGROUND

Transthoracic epicardial catheter ablation effectively controls recurrent ventricular tachycardia (VT) in patients with Chagas' disease in whom epicardial circuits predominate. Epicardial circuits also occur in postinfarction VT.

METHODS

Fourteen consecutive patients aged 53.6 +/- 14.5 years with postinfarction VT related to the inferior wall were studied. The VT cycle length was 412 +/- 51 ms. Two patients had previously undergone unsuccessful standard endocardial radiofrequency energy (RF) ablation. The VT was incessant in one patient. Left ventricular angiography showed inferior akinesia in 13 patients and an inferior aneurysm in 1 patient. Ablation was performed with a regular steerable catheter placed into the pericardial sac by pericardial puncture.

RESULTS

The pericardial space was reached in all patients. Electrophysiologic evidence of an epicardial circuit was present in 7 of 30 VTs. Due to a high stimulation threshold, empirical thermal mapping was the only criterion used to select the site for ablation. Three VTs were interrupted during the first RF pulse. Two pulses were necessary to render it noninducible in 3 patients (1 VT per patient). In the remaining 4 VTs, 3, 3, 4 and 5 RF pulses, respectively, were used. The overall success was 37.14% (95% confidence interval, 11.83% to 62.45%). Patients are asymptomatic for 14 +/- 2 months.

CONCLUSIONS

Postinfarction pericardial adherence does not preclude epicardial mapping and ablation to control VT related to an epicardial circuit in postinferior wall myocardial infarction.